Compact, handheld or "palm" computing devices have provided a convenient means for users to store and retrieve data via a portable interface. Such devices typically incorporate a viewable display screen for textual or numerical input or output; an input device such as a small keypad, stylus or touch screen; and a network or modem interface for receiving program data or sharing data with other computers. Because the number of users of handheld computing devices has been steadily increasing, it has become desirable to integrate voice communications capability into these devices to allow users the additional convenience of portable cellular telephones.
Typically, voice communications in handheld and palm computing devices are implemented using several methods, each of which has its own shortcomings. For example, a headset may be used consisting of earphones and a microphone on a common cable attached to the computing device. In such a system, the cable and headset may be a cumbersome and inconvenient accessory to transport and use. Some computing devices include a speaker embedded at one end and a microphone embedded in the other end. The device may be used in the same manner as a conventional telephone handset. However, with such a device, it becomes nearly impossible to use the computing device for voice communications and to simultaneously use the device for data input or retrieval. Still other computing devices include a wired or wireless handset which is capable of both voice transmission and reception. In such devices, however, both the handset and the computing device require high power-consumption transmitters and receivers. Finally, some computing devices incorporate a speakerphone which includes both a speaker for voice reception and a microphone for voice transmission. These devices, however, do not allow the user to engage in private voice communications.
Thus, it is desirable for handheld computing devices to utilize speakerphones for voice communications in order to free the hands for data entry. Voice communication devices that integrate speakerphones can utilize a single speaker as a speakerphone speaker or a private, earpiece speaker. When using a single speaker, however, the user should be protected from the speaker accidentally emitting a sound pressure level associated with a speakerphone when the device is being used as an earpiece for private conversation. Even with a manual switch installed to switch from an earpiece mode to a speakerphone mode, errors in switching could result in considerable discomfort, increased power consumption, and breaches of privacy.
Therefore, there is a need for a handheld computing device that allows the user to conveniently engage in speakerphone and private conversation without the shortcomings described above.